Given that, AB ∥ CD and ∠QMD = 100°
We know that, from the figure ∠QMD + ∠QMC = 180° is a linear pair,
∠QMC = 180° – ∠QMD
∠QMC = 180° – 100°
∠QMC = 80°
Corresponding angles are
∠DMQ = ∠BLM = 100°
∠CMQ = ∠ALM = 80°
Vertically Opposite angles are
∠DMQ = ∠CML = 100°
∠BLM = ∠PLA = 100°
∠CMQ = ∠DML = 80°
∠ALM = ∠PLB = 80°